The following studies on the mechanism by which human adenoviruses replicate and transform cells are in progress: 1. Replicate intermediates in adenovirus DNA replication and their association with nuclear membranes. 2. Transcription of adenovirus genomes in vivo and in vitro by the transcription complex. 3. Isolation of individual adenovirus mRNA molecules and studies on their strand selectivity and their content in poly adenylic tracts. 4. In vitro translation of adenovirus mRNA molecules. 5. Integration of viral DNA sequences in transformed cells. 6. Isolation of cell transforming proteins and tumor antigens.